70 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



TURBONILLA (PYRGOLAMPROS) ALASKANA, new species. 

 Plate 6, fig. 9. 



Shell elongate-conic, wax yellow, with a broad, peripheral, light- 

 brown band and a narrow one immediately below the sunnnit ; these 

 are best seen in the aperture. (Nuclear whorls decollated in all our 

 specimens.) Post-nuclear whorls increasing very slowly in diameter 

 in the first three turns, then more rapidly. The summits of succeed- 

 ing turns fall a little below the periphery, which gives the whorls an 

 overhanging appearance. The whorls are marked by very strong, 

 well elevated, broad, rounded, irregularly slanting axial ribs which 

 become slightly widened and flattened both at the summit and at the 

 periphery. There are about 18 of them upon all but the last turn; 

 upon this there are about 22. Intercostal spaces about as wide as 

 the axial ribs. Sutures strongly impressed. Peripher}^ of the last 

 whorl somewhat angulated, base moderately long, well rounded, 

 marked by feeble extensions of the axial ribs and many fine, closeh^ 

 spaced, waA^y spiral striations; the latter also mark the spaces between 

 the sutures. Aperture moderately large, ovate, posterior angle acute ; 

 outer lip moderately thick; columella oblique, curved andstrongly 

 revolute; parietal wall covered by a strong callus. 



The type and seven specimens (Cat. no. 160206, U.S.N.M.) were col- 

 lected at St. Paul, Kadiak, Alaska, in 13 fathoms, mud bottom, by 

 Dr. W. H. Dall. The type has lost the nucleus and probably the first 

 one and one-half post-nuclear turns. The nine remaining measure: 

 Length 8 mm., diameter 2.6 mm. The following specimens were all 

 collected by Doctor Dall (Cat. no. 205149, U.S.N.M.). Nine specimens 

 from Chagafka Cove, Kadiak, Alaska; (Cat. no. 205150 U.S.N.M.), 

 one specimen from Granite Cove, Port Althorp, Alaska, in 8 fathoms 

 on sand bottom; (Cat. no. 160209, U.S.N.M.) three specimens from 

 Sitka Harbor, Alaska, in 12 fathoms on mud and gravel bottom. 



TURBONILLA rPYRGOLAMPROS) CHOCOLATA Carpenter. 



Plate 5, figs. 9, 9r;. 



Chemnitzia chocolata Carpexter, Proc. Oal. Acad. Sci., 1865, p. 220. 



Shell slender, elongate-conic, uniformly golden-brown, shining. 

 Nuclear whorls very small, planorboid, two and one-half, having 

 their axis at right angles to that of the succeeding turns; not immersed. 

 Post-nuclear whorls rather high between the sutures, slightly shoul- 

 dered at the summit, flattened on the posterior three-fourths between 

 the sutures; rounding on the anterior fourth to the somewhat con- 

 tracted suture. Axial ribs slightly retractive, well rounded, 22 upon 

 the first eight whorls, 24 upon the ninth, and 28 upon the tenth; on 

 the penultimate whorl they are poorly developed, split, and other- 

 wise indicating a senile stage. Sutures well impressed. Periphery 

 and base of the last whorl inflated and well rounded. The entire 



